CDK5 and cancer: Surfactin C15 caused a significant anticancer activity involving multiple modes of action: downregulation of the expression of cancer stem cell marker CD133, upregulation of pro-apoptotic factors (PUMA, CHOP, and DR5), and modulation of regulators of the cell cycle (CCNE1, CDK5, and CDKN1A). Additionally, surfactin C15 triggered necrotic cell death, validated by increased release of lactate dehydrogenase and increased necrotic cells observed via flow cytometry analysis